Refrigerant system expansion means

ABSTRACT

A refrigerant expansion or metering device employed in refrigeration systems including compression means, a first heat exchanger and a second heat exchanger, comprising a fluid regulator forming a vortex chamber, through which refrigerant is passed. Disposed within the vortex chamber is movable means operable to vary the path of flow and to vary the rate of flow of refrigerant through the vortex chamber. Control means vary the position of the movable means in response to changes in temperature in the refrigeration system.

D United States Patent 11 13590592 [72] Inventor Charles N. High [56]ReferencesCited 32 3:? UNITED STATES PATENTS figs- Jung 1969 3,371,5013/1968 Rhea 62/160 (45] Patented 3. 3,488,975 1/1970 Nelson 62/197 [73]Assign carriercorpmfion 3,498,074 3 1970 Fineblum 62/197 Syracuse, N.Y.Primary Examiner-Meyer Perlin [54] REFRIGERANT SYSTEM EXYANSION MEANSAttorneys-Harry G. Martin, Jr. and J. Raymond Curtin ABSTRACT: Arefrigerant expansion or metering device employed in refrigerationsystems including compression means, a first heat exchanger and a secondheat exchanger, comprising a fluid regulator forming a vortex chamber,through which refrigerant is passed. Disposed within the vortex chamberis movable means operable to vary the path of flow and to vary the rateof flow of refrigerant through the vortex chamber. Control means varythe position of the movable means in response to changes in temperaturein the refrigeration system.

PATENTEUJUL-BIQ?! 3,590,592

luv/mum.

CHARLES N. HIGH.

BY/FW ATTORNEY.

lltlElFMllGEll tfiliNT SYSTEM EXPANMOW MlEAhlfi BACKGROUND OF THElNVENTlON This invention relates to refrigeration systems and moreparticularly, to an improved expansion means for refrigeration systems.

Refrigeration systems employ, as a means for expanding the relativelyhigh-pressure liquid refrigerant leaving the system condenser, either afixed restrictor, commonly known as a capillary tube, or a variablerestrictor, such as a thermal expansion valve. While fixed restrictorsare relatively inexpensive, their lack of adaptability to change insystem load limits their usefulness. On the other hand, the variablerestrictor, such as a thermal expansion valve, incorporates acontrolling mechanism for varying the valve setting in response tochanges in refrigerant temperature exiting from the evaporator due tovariations in load conditions in the system. However, variablerestrictors are relatively expensive and are generally the subject ofnumerous repairs.

The invention herein disclosed relates to a novel expansion device, onethat is relatively inexpensive to manufacture and relatively maintenancefree, and one that is adaptable to changes of temperature of therefrigerant exiting from the evaporator.

SUMMARY OF THE lNVENTlON The invention herein disclosed may be employedin a refrigeration system including compression means, a first heatexchanger for receiving refrigerant discharged by the coin pressionmeans, and a second heat exchanger connected to the suction side of thecompression means. The invention herein disclosed communicates the firstheat exchanger with the second heat exchanger. Relatively high-pressureliquid refrigerant flows from the first heat exchanger through the invention functioning as the system refrigerant expansion device. Therefrigerant leaves the invention as a relatively lowpressure mixture ofliquid and gas.

The refrigerant expansion device includes a fluid regulator forming avortex chamber through which the refrigerant passes en route to thesecond heat exchanger. The refrigerant inlet in the chamber is insubstantially tangential communica tion therewith. The refrigerantpassing through the chamber undergoes an approximate 90 change indirection.

Disposed in the chamber, transverse to the path of flow of therefrigerant, is a movable means, such as a plunger. Control means,operable to selectively withdraw the movable means from the chamber orproject the movable means further into the chamber, functions inaccordance with changes in the temperature of the refrigerant exitingfrom the second heat exchanger. when the plunger is substantiallywithdrawn from the chamber, the vortex effect on the refrigerant flow isat its maximum, the refrigerant flow through the chamber being greatlyimpeded. As the plunger is projected in the chamber, the vortex effectis reduced, the refrigerant flow through the chamber being therebyincreased.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE of the drawing is aschematic view, partially in section, of a refrigeration systemincorporating the novel refrigeration expansion means.

DESCRIPTION OF THE PREFERRED EMBODlMENT Referring to the single FIGUREof the drawing, there is shown a refrigeration system employing thenovel refrigeration expansion device herein disclosed. The refrigerationsystem 10 is typical of the type used with air-conditioning units, suchas a room air conditioner. Refrigeration system 10 has a suitablerefrigerant compressor llll which, while illustrated as a reciprocatingcompressor, may comprise any suitable compressor such as a rotary,centrifugal, etc. Refrigerant line 12 conducts the relativelyhigh-pressure gaseous refrigerant discharged from compressor ill to afirst heat exchanger l3, functioning as the system condenser.

The high-pressure, gaseous refrigerant condenses in the first heatexchanger l3 by therethrough in heat transfer relationship with arelatively cold medium such as air. The liquid refrigerant formedthereby passes to the system expansion or metering means 15 via conduitM.

Expansion device 15 reduces the pressure of the liquid refrigerant andcontrols the flow thereof to the remaining por tion of the system. Adetailed discussion of the novel expansion device l5 will be foundhereinafter.

The reduced pressure liquid refrigerant is fed via line 116 to a secondheat exchanger l7 functioning as the system evaporator. The thermalinterchange effected by evaporator 17 between the refrigerant and themedium being cooled, for example air, vaporizes or evaporatesrefrigerant while extracting heat from the medium being cooled. Asuitable circulating means such as a fan (not shown) may be provided forbringing the medium being cooled into heat transfer relation with therefrigerant in the evaporator lll'. Vaporized refrigerant leavingevaporator ll? returns through line llfi to the inlet or suction side ofthe compressor llll.

The refrigerant expansion or metering means l5 disclosed herein is avortex-type fluid regulator. The regulator comprises a shell W forming agenerally cylindrical vortex chamber 20. Refrigerant line M, whichconnects to inlet 21 in the peripheral wall of shell l9, dischargesduring system operation a stream of liquid refrigerant into vortexchamber 24). lnlet 2ll is in substantially tangential communication withchamber 211i. Outlet 22 in end wall 23 of the regulator communicateswith refrigerant line in. As is manifest, refrigerant entering vortexchamber 2 9 undergoes an approximate change in direction for dischargethrough outlet 22 into line llfi.

Movably disposed in the chamber 20, transverse to the flow path of therefrigerant, is obstruction means 241 such as a rod or plunger. Thepurpose of obstruction means 24 is to vary the vortex effect created inchamber 20 and hence vary the discharge of refrigerant to line To,thence to evaporator 17. Control means associated with movableobstruction means 24 acts to selectively withdraw or project the movablemeans 24 from or into chamber 24] in response to changes in temperaturesof the refrigerant exiting from the evaporator 17. As movable means 24is projected further into chamber 20, the vortex effect on therefrigerant flow is lessened; movable obstruction means 24 reduces therestrictive effect of a vortex flow path. Conversely, the furthermovable means is withdrawn from chamber 20, the greater is the vortexeffect on the refrigerant flow. Thus, at peak cooling loads, it isdesirable for obstruction means 24 to extend fully into chamber 20,while at minimal cooling loads on the system, it is desirable for themeans 2% to be substantially completely withdrawn from the chamber 2t]!and thus the refrigerant flow therethrough is greatly impeded asdesired.

The control means employed with the preferred embodiment of the novelrefrigerant expansion device includes an expandable bellows 25 connectedto movable means 24. The bellows .25 is disposed in a housing 30,preferably formed integrally with shell W. The inner surface of the wallof the bellows 25 defines a chamber 2d containing a charge ofrefrigerant, such as lit-22. The outer surface of the wall of thebellows 25 and the inner surface of the housing 30 define a chamber 31.Obstruction means 24 movably disposed within chamber Sill extendstherefrom into chamber 20 via passageway 29 formed in the wall of shell19. Sealing means 3d is employed to prevent an appreciable quantity ofrefrigerant from flowing to chamber 31 from chamber 20.

Communicating refrigerant line lid to chamber 31 is conduit 33. Conduit33 passes part of the refrigerant exiting from the refrigerant expansiondevice 15 to chamber 311, thus substantially filling the chamber 311with refrigerant. The pressure of the refrigerant in chamber Illl exerts.a compressive force on the bellows, thereby acting to withdraw movablemeans 24 from chamber 20. Acting in conjunction with the force developedby the refrigerant in chamber 31 is the inherent compressive force ofthe bellows 25. Acting in opposition to these two forces is the forcedeveloped by the refrigerant in chamber 28, acting to expand the bellowsand thus to project movable means 24 further into chamber 20.

Connected to bellows 25 via capillary tube 32 is feeler bulb 27,arranged to respond to the temperature of the refrigerant exiting fromthe evaporator 17. Preferably, bulb 27 is attached to the system suctionline 18. A charge of refrigerant is contained in the bulb 27.

As the temperature of the refrigerant exiting from the evaporator 17increases, the temperature and pressure of the refrigerant chargecontained in bulb 27 correspondingly increases. The increase in pressureis transmitted via capillary tube 32 to the refrigerant charge containedin bellows 25, thereby affording a corresponding increase in thepressure of the refrigerant contained in chamber 28. The pressurizedrefrigerant vapor thence exerts a force greater than the compressiveforce of the bellows and the force developed by the refrigerantcontained in chamber 31, thereby acting to expand the bellows 25. Theexpanding bellows 25 projects movable member 24 further into chamber 20,thereby increasing the flow of refrigerant to evaporator 37 as desired.

Conversely, if the temperature of the refrigerant exiting from theevaporator 17 decreases, the resulting force acting on bellows 25 willcompress the bellows, and thus will reduce the amount movable member 24projects into chamber 20. The flow of refrigerant to evaporator 17 willthereby be decreased as desired.

It should be understood, other methods of controlling the movement ofmeans 24 may be utilized. In addition, the compressive force of thebellows may be made adjustable, to vary the superheat control in amanner well known to those skilled in the art.

The novel expansion device is relatively inexpensive to manufacture andis relatively maintenance free. in addition, the device will beadaptable to changes in refrigerant temperature exiting from theevaporator to obtain optimum heat transfer performance from theevaporator, and in addition, will prevent possible damage to thecompressor by liquid refrigerant entering the suction side of thecompressor.

While I have described and illustrated a preferred embodiment of myinvention, it will be understood that my invention is not limitedthereto, but may be otherwise embodied within the scope of the followingclaims.

lclaim:

l. A refrigeration system comprising compression means, a first heatexchanger for receiving refrigerant discharged by said compressionmeans; refrigerant metering means connected with said first heatexchanger; and a second heat exchanger arranged between said refrigerantmetering means and said compression means, said components beingconnected to form a refrigerant flow cycle, said refrigerant meteringmeans including:

A. a fluid regulator forming a vortex chamber through which refrigerantpasses en route to said second heat exchanger, said vortex chamberhaving plunger means movably disposed therein; and

B. control means to vary the position of said plunger means in saidvortex chamber, in response to the temperature of refrigerant exitingfrom said second heat exchanger, to vary the path of flow and to varythe rate of flow of said refrigerant through said vortex chamber inaccordance with changes in system cooling load.

2. A refrigeration system in accordance with claim 1 wherein saidcontrol means includes:

A. a bellows having a refrigerant charge contained therein operablyconnected to said plunger means; and

B. means operable to sense the temperature of said refrigerant leavingsaid second heat exchanger, said means being further operable toincrease the pressure of said refrigerant charge in said bellows as thetemperature of the re rlgerant leaving the second heat exchangerincreases to move said plunger means further into said vortex chamberand to decrease the pressure of said refrigerant charge in said bellowsas the temperature of the refrigerant leaving the second heat exchangerdecreases to withdraw said plunger means from said vortex chamber.

3. A refrigerant-metering device employed in refrigeration systemsoperable to expand relatively high-pressure liquid refrigerantcomprising:

A. a fluid regulator forming a vortex chamber through which refrigerantis passed;

B. refrigerant inlet means into said vortex chamber;

C. refrigerant outlet means from said vortex chamber;

D. plunger means movably disposed in said vortex chamber to vary theflow path of refrigerant therethrough; and

E. control means operable to vary the position of said plunger means insaid vortex chamber in response to predetermined refrigeration systemconditions, to vary the path of flow and to vary the rate of flow ofsaid refrigerant through said vortex chamber in accordance with changesin said system conditions.

4. A refrigerant metering device in accordance with claim 3 wherein saidrefrigerant inlet means is in substantially tangential communicationwith said vortex chamber.

5. A refrigerant metering device in accordance with claim 3 wherein saidrefrigerant passing through said vortex chamber undergoes an approximatechange in direction from entering said chamber at said inlet means toleaving said chamber at said outlet means.

6. A refrigerant-metering device in accordance with claim 3 wherein saidcontrol means include:

A. a bellows having a refrigerant charge contained therein,

operably connected to said plunger means; and

B. means operable to sense the temperature of refrigerant in one portionof said refrigeration system, said means being further operable toincrease the pressure of said refrigerant charge in said bellows as thetemperature of the sensed refrigerant increases, to move said plungermeans further into said vortex chamber; and to decrease the pressure ofsaid refrigerant charge in said bellows as the sensed refrigeranttemperature decreases to withdraw said plunger means from said vortexchamber.

7. A method of regulating the flow of refrigerant in a refrigerationsystem comprising compression means, a first heat exchanger and a secondheat exchanger comprising the steps of:

A. energizing said compression means to circulate said refrigerantthrough said system;

B.- directing the flow of refrigerant from the first heat exchanger tothe second heat exchanger through a path including a vortex;

C. withdrawing mechanical flow obstruction means, disposed within saidvortex in the path of refrigerant flow, to restrict the flow ofrefrigerant from the first heat exchanger to said second heat exchangeras the cooling load on said system increases; and

D. projecting said mechanical obstruction means, disposed within saidvortex chamber in the path of refrigerant flow, to increase the flow ofrefrigerant from the first heat exchanger to said second heat exchangeras the cooling load on said system increases.

1. A refrigeration system comprising compression means, a first heatexchanger for receiving refrigerant discharged by said compressionmeans; refrigerant metering means connected with said first heatexchanger; and a second heat exchanger arranged between said refrigerantmetering means and said compression means, said components beingconnected to form a refrigerant flow cycle, said refrigerant meteringmeans including: A. a fluid regulator formiNg a vortex chamber throughwhich refrigerant passes en route to said second heat exchanger, saidvortex chamber having plunger means movably disposed therein; and B.control means to vary the position of said plunger means in said vortexchamber, in response to the temperature of refrigerant exiting from saidsecond heat exchanger, to vary the path of flow and to vary the rate offlow of said refrigerant through said vortex chamber in accordance withchanges in system cooling load.
 2. A refrigeration system in accordancewith claim 1 wherein said control means includes: A. a bellows having arefrigerant charge contained therein operably connected to said plungermeans; and B. means operable to sense the temperature of saidrefrigerant leaving said second heat exchanger, said means being furtheroperable to increase the pressure of said refrigerant charge in saidbellows as the temperature of the refrigerant leaving the second heatexchanger increases to move said plunger means further into said vortexchamber and to decrease the pressure of said refrigerant charge in saidbellows as the temperature of the refrigerant leaving the second heatexchanger decreases to withdraw said plunger means from said vortexchamber.
 3. A refrigerant-metering device employed in refrigerationsystems operable to expand relatively high-pressure liquid refrigerantcomprising: A. a fluid regulator forming a vortex chamber through whichrefrigerant is passed; B. refrigerant inlet means into said vortexchamber; C. refrigerant outlet means from said vortex chamber; D.plunger means movably disposed in said vortex chamber to vary the flowpath of refrigerant therethrough; and E. control means operable to varythe position of said plunger means in said vortex chamber in response topredetermined refrigeration system conditions, to vary the path of flowand to vary the rate of flow of said refrigerant through said vortexchamber in accordance with changes in said system conditions.
 4. Arefrigerant metering device in accordance with claim 3 wherein saidrefrigerant inlet means is in substantially tangential communicationwith said vortex chamber.
 5. A refrigerant metering device in accordancewith claim 3 wherein said refrigerant passing through said vortexchamber undergoes an approximate 90* change in direction from enteringsaid chamber at said inlet means to leaving said chamber at said outletmeans.
 6. A refrigerant-metering device in accordance with claim 3wherein said control means include: A. a bellows having a refrigerantcharge contained therein, operably connected to said plunger means; andB. means operable to sense the temperature of refrigerant in one portionof said refrigeration system, said means being further operable toincrease the pressure of said refrigerant charge in said bellows as thetemperature of the sensed refrigerant increases, to move said plungermeans further into said vortex chamber; and to decrease the pressure ofsaid refrigerant charge in said bellows as the sensed refrigeranttemperature decreases to withdraw said plunger means from said vortexchamber.
 7. A method of regulating the flow of refrigerant in arefrigeration system comprising compression means, a first heatexchanger and a second heat exchanger comprising the steps of: A.energizing said compression means to circulate said refrigerant throughsaid system; B. directing the flow of refrigerant from the first heatexchanger to the second heat exchanger through a path including avortex; C. withdrawing mechanical flow obstruction means, disposedwithin said vortex in the path of refrigerant flow, to restrict the flowof refrigerant from the first heat exchanger to said second heatexchanger as the cooling load on said system increases; and D.projecting said mechanical obstruction means, disposed within saidvortex chamber in the path of refrigerant flow, to increase the fLow ofrefrigerant from the first heat exchanger to said second heat exchangeras the cooling load on said system increases.